There have been lots of questions about why we chose to do our Part
2 article using the 3.7 Cats from ATI rather than waiting until today to use the brand
new 3.8 version of the drivers. Our reasoning behind this decision was two
fold: we wanted to get yesterday's article out as a timely follow-up to last
weeks Part 1 of the series, and we also wanted to do a comparison between the
3.7 Cats and the new drivers.

With the Radeon XT series, ATI introduced a new feature called OverDrive.
The basic principle of OverDrive is that the GPU can run at higher clock speeds
if it is running cool enough, so as long as the chip is cool enough it will
safely overclock. ATI’s OverDrive technology uses a combination of a
hardware thermal diode and software support to keep track of the temperature
of the GPU. If the temperature is within certain predefined limits, the drivers
will increase the GPU clock speed by a safe margin defined by ATI. Once the
GPU heats up again to the point where ATI can’t guarantee no degradation
of chip-life, the drivers will underclock the GPU to as low as its original
clock speed (but never lower). The Catalyst 3.8 drivers enable support for
the thermal diode present on the Radeon 9800XT and the Radeon 9600XT; note
that none of the previous Radeon cards have the thermal diode and thus will
not support OverDrive.

The whole idea that a reputable company would be building any kind of overclockability
into their product has really intrigued us. We had lots of questions like:
how much will performance improve, and will stability be an issue. How much
can we really get for nothing? Well, the answers may surprise, but even if
they don't, there are some very interesting implications from the way things
have played out. But before we get to that, we are going to take a look at
the new interface, and then go through all the games in the list one more time.

This time for our testing, we will only be doing 1600x1200 with AA/AF on and
off for games that have the option. All of our graphs will use the data we
collected for Part 2 and compare it to what we found after we received our
drivers from ATI yesterday. It’s been a long night, but it was well worth
it.

We used the same benchmarks on the same FX51 system as in Part
2. Let’s
let the show begin...

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62 Comments

#3 has the best comment, is there a way to get the info of the Core/Mem speed being used? It just seems that outside of the OpenGL benches, the increases were too small to really know if Overclocking was happening or not. IOW, the gains were small enough to fall into statistical anomaly.

Certainly any gain is good, but I was able to acheive better improvements from overclocking on a number of video cards, either ATI is being really conservative(which makes sense since they have Warranty concerns) or the Overdrive isn't working(possible, but I'd choose conservatism as the reason).

I'd also be interested in the results of using exotic cooling(not that I'd use it). It would be especially interesting to see if the Overdrive feature is able to recognize Graphic Corruption or whether it is solely concerned with temperature.Reply

Then please explain how it is possible that I have a DX9 game on my machine at the moment. (A TWIMTBP even :-)

But if the rare DX9 games at the moment are not the ones you are interested in, then indeed it is better to wait. (if your card is still fast enough for the current DX8 games). But if you do need to buy a new card at this moment, (maybe the old one broke) then the choice is very clear.Reply

You're an idiot #8. HL2 won't be out for months and there are basically ZERO DX9 games out. Therefore, it'd be stupid to buy a card now based on basically no data. And no, ShaderMark 2.0 is barely hard data. Reply

I am extremely perplexed myself with the conclusion. Specifically, the last sentence:

"Even so, we are still standing behind our wait and see recommendation with respect to purchasing a card intended for use with the coming DX9 games."

Hello? Anandtech? If you are buying these cards with an eye to DX9 performance, the choice is clear. ATI. At best, nVidia "optimizations" might get DX9 performance on par with ATI's. At worst, it's about 50% of ATI performance.

It's only if you DON;'T care about DX9 performance that the FX line even becomes an option.

You should do another comparison that puts some extra cooling on the card, either by replacing the stock heatsink/fan or simply blowing more air across the card as if someone set a card cooler next to the video card. If the drivers worked well, this should noticeably improve card performance in a fairly inexpensive way.Reply